I'm playing an earthquake Barbarian and i just wanted to know what you think, which class is the fastest in T6 solo-faming. I heard Witch Doctors are also really fast and based on MannerCookie Crusaders are also strong.

No way crusader is faster than a wizard, Avoid had a few sub 5 min rift clears that are on his twitch page ( I think that is where is seen them). I mean yeah a few with conduit but without I think he averages 7-8 min.